The Silvertown Tunnel (STT) is a new, approximately 1.4 km long twin bore TBM road tunnel located in East London crossing beneath the River Thames. It connects the Greenwich Peninsula to Silvertown.
The main tunnels was constructed as twin-bore TBM tunnels which are connected by 7 No. cross passages.
The alignment for the tunnels and cross passages passes through Made Ground, Alluvium, River Terrace deposits, London Clay, Harwich Formation, and Lambeth Group sediments.
The cross passages were built using sprayed concrete as primary lining followed by waterproofing and reinforced concrete for permanent tunnel support. CPs 2 to 6 was constructed using ground freezing for temporary ground stabilisation. CP1 was built in treated ground (soft piles) while CP 7 will be built using groundwater depressurisation for the Lambeth Group sediments.
Detailed Design Consultancy:
Gall Zeidler Consultants was responsible for the developed and detailed design of the special TBM segments for the CP openings, ground freezing and cross passage design.